This invention relates to repairing cartilage, for example, articular cartilage on the patella and tibia.
Articular cartilage that is damaged (e.g., torn or excessively worn) may be repaired in a variety of ways. For example, the damaged cartilage may be shaved or scraped from the bone surface, thereby causing bleeding which stimulates the growth of fibrocartilage. Similarly, small holes may be drilled in the bone to promote bleeding and fibrocartilage growth. Alternatively, an allograft (e.g., cartilage grown in vitro from cartilage tissue removed from the patient) may be implanted by attaching a periosteum membrane (harvested, e.g., from the patient""s tibia) to the bone surface and injecting the allograft beneath the membrane. The periosteum provides a healthy environment which promotes further cartilage cell growth.
In one general aspect, a set of surgical instruments for repairing a cartilage surface on a posterior surface of the patella includes a first instrument and a second instrument. The first instrument includes a channel defining a longitudinal axis that extends from the channel to intersect an anterior surface of the patella. The second instrument is mountable to the first instrument and includes a surface that is configured to be placed against a posterior surface of the patella. The longitudinal axis of the channel is at an angle to the surface of the second instrument when the second instrument is mounted in the first instrument.
Embodiments of the set of surgical instruments may include one or more of the following features. For example, the angle may be between approximately 80xc2x0 and 100xc2x0. The angle also may be at approximately 90xc2x0. The set of surgical instruments may further include a guide wire configured to be inserted into the channel in the first instrument and to drill a passage from an anterior opening on the anterior surface of the patella to a posterior opening on the posterior surface of the patella. The longitudinal axis of the passage through the patella is at an angle to the posterior surface of the patella at the posterior opening. The angle may be between approximately 80xc2x0 and 100xc2x0. The angle also may be at approximately 90xc2x0. The set of surgical instruments may still further include a drill that can be passed over the guide wire and into the anterior opening. The drill is operable to enlarge the passage in the patella, from the anterior opening to the posterior opening.
The set of surgical instruments may still further include a delivery instrument to deliver a cartilage graft into the passage in the patella. The delivery instrument has an interior channel passage that extends between an open distal end and an open proximal end, and a flange at the distal end. The flange can be inserted into the anterior opening to deliver the cartilage graft through the interior channel into the passage in the patella. The delivery instrument may include a window formed in a wall. The window is open to the interior channel such that the cartilage graft can be observed through the window during delivery through the interior channel.
The set of surgical instruments may still further include an insertion instrument that is insertable into the interior channel of the delivery instrument to advance the cartilage graft from the delivery instrument through the anterior opening in the patella into the passage in the patella.
The first instrument may be a director handle that includes the channel and a slot that receives the second instrument. The second instrument may be a guide that includes a foot that is flush with a posterior surface of the patella when the foot is pressed against the patella. The foot may include a lower surface and a generally flat upper surface opposite the lower surface, with the foot configured to be pressed against the posterior surface of the patella. The generally flat upper surface may include a central channel passing between an opening in the upper surface and an opening in the lower surface. The central channel may have a diameter that is reduced from the upper surface to the lower surface. A longitudinal axis of the central channel may be perpendicular to the generally flat upper surface of the foot. The distal foot may be pivotably attached to the guide.
The set of surgical instruments may further include a tube having an interior channel. The tube may be configured to be inserted into the channel of the director handle and to receive a guide wire in the interior channel for drilling a hole in the patella.
The set of surgical instruments may further include a drill having an interior channel. The interior channel is designed to be inserted over a guide wire to enlarge a hole drilled by the guide wire in the patella.
The set of surgical instruments may further include an offset tool that includes a handle, a probe, and a guide. The handle has a distal end and the probe is attached to the distal end and extends perpendicularly from a face of the handle. The guide is attached to the distal end of the handle, offset from the probe, and has an inner shaft with a longitudinal axis that is substantially parallel to the probe. The longitudinal axis of the guide is offset from a longitudinal axis of the probe by approximately 0.1 to 0.3 inches. The longitudinal axis of the guide may be more particularly offset from the longitudinal axis of the probe by approximately 0.18 inches.
The set of surgical instruments may further include a chisel, a chisel guard, and a tamp. The chisel has a tip and a longitudinal shaft passing through the tip. The chisel guard has a shaft and a flanged end. The chisel guard can be placed around the chisel by inserting the chisel into the chisel guard""s shaft. The tamp is designed to be inserted into the longitudinal shaft of the chisel.
The set of surgical instruments may further include a tapered bone plug compressor. The compressor includes a longitudinal shaft passing between a first opening and a second opening, and the diameter of the shaft increases from the second opening to the first opening.
In another embodiment of the set of surgical instruments, the first instrument may be a guide tube and the second instrument may be a clamp body. The guide tube includes the channel and a window that allows visual inspection of the channel. The clamp body includes an upper arm and a lower arm connected by an extension. The upper arm includes a channel having a longitudinal axis and in which the guide tube is inserted. The lower arm includes a foot having a channel aligned with the longitudinal axis of the channel of the guide tube and of the channel of the upper arm.
The upper arm and the lower arm may be connected to the extension at right angles. The upper arm may be connected to the extension such that the upper arm and the lower arm are parallel. The guide tube may be threadably received in the channel in the upper arm.
The foot may have a flat upper surface that is configured to contact a bony surface. The foot may have a flat upper surface that is perpendicular to the longitudinal channel of the guide tube. The foot may be mounted to the lower arm in a fixed relationship or a pivotal relationship. The foot also may be in the form of a ring having a channel through it.
The set of surgical instruments may further include a drill guide, having a longitudinal channel, which is designed to be inserted into the channel in the guide tube. The set of surgical instruments may still further include a guide wire that is insertable into the longitudinal channel of the drill guide.
In another general aspect, a surgical method of repairing an articular cartilage surface on a posterior surface of the patella includes placing a first instrument through a first incision so that the first instrument is adjacent to an anterior surface of the patella, placing a second instrument through a second incision so that the second instrument is located between the posterior surface of the patella and the femoral head, drilling a passage from the anterior surface of the patella to the posterior surface of the patella, inserting a graft into the anterior surface opening of the passage, and inserting the graft further into the passage. The passage passes between an anterior surface opening and a posterior surface opening.
Embodiments of the surgical method may include one or more of the following features. For example, the passage through the patella may be perpendicular to the posterior surface of the patella adjacent to the posterior surface opening. The first instrument may include a channel having a longitudinal axis that extends from the channel to the anterior surface opening of the patella, and through which a guide wire can be inserted to drill the passage through the patella. The second instrument may be mountable to the first instrument and may include a surface that is configured to be placed against a posterior surface of the patella. When the second instrument is mounted in the first instrument, the longitudinal axis of the channel of the first instrument is perpendicular to the surface of the second instrument.
The surgical method may further include enlarging the drilled passage through the patella. Enlarging the passage includes passing a drill over the guide wire, inserting the drill into the anterior surface opening, and enlarging the passage between the anterior surface opening and the posterior surface opening.
In the surgical method, inserting the graft into the anterior surface opening of the passage may further include placing a delivery instrument against the anterior surface opening. The delivery instrument includes an interior channel that extends between an open distal end and an open proximal end, and a flange at the distal end. The flange is designed to be inserted into the anterior surface opening to deliver a cartilage graft through the interior channel into the passage in the patella. The delivery instrument may include a window that is formed in a wall and is open to the interior channel such that the cartilage graft can be visually inspected during delivery through the interior channel. Inserting the graft further into the passage may include inserting an insertion instrument into the interior channel of the delivery instrument and advancing the cartilage graft from the delivery instrument into the passage in the patella through the anterior opening in the patella.
In the surgical method, the first instrument may be a director handle and a tube, and the second instrument may be a patellar guide that includes a foot having a generally flat surface. The first and second instruments are assembled by installing the patellar guide in a slot of the director handle and inserting the tube in a channel of the director handle. Placing the first instrument adjacent to the anterior surface of the patella includes placing a distal end of the tube against the anterior surface of the patella through a first incision. Placing the second instrument adjacent to the posterior surface of the patella includes inserting the second instrument in a second incision and placing the generally flat surface of the foot against the posterior surface of the patella.
The surgical method may further include inserting a guide wire through a longitudinal channel of the tube, inserting the guide wire into the first incision, and drilling a passage with the guide wire through the patella. The passage passes between the anterior surface and the posterior surface of the patella. The passage through the patella may be perpendicular to the posterior surface of the patella. The guide wire may enter a channel in the foot when the guide wire passes through the posterior surface of the patella.
The surgical method may further include removing the director handle and the patellar guide and inserting a drill over the guide wire to enlarge the passage through the patella. The surgical method also may further include drilling at least one additional passage through the patella, with the additional passage being offset from the first passage.
Drilling the additional passage may include providing an offset tool, placing the probe in the first passage, placing the guide wire through the bullet and the inner shaft of the guide, and drilling the additional passage. The offset tool includes a handle having a distal end, a probe attached to the distal end and extending perpendicularly from a face of the handle, and a guide attached to the distal end. The guide is offset from the probe and has an inner shaft with a longitudinal axis that is substantially parallel to the probe. The additional passage is drilled such that it is offset from the first passage by an offset distance from the probe and the longitudinal axis of the inner shaft.
The surgical method may further include harvesting a cartilage replacement graft. Harvesting the cartilage graft may include providing a chisel, a chisel guard, and a tamp. The chisel has a tip and a hollow longitudinal shaft passing through the chisel. The chisel guard has a hollow shaft and a flanged end. The chisel guard""s shaft is configured to surround the chisel. The tamp is configured to be inserted into the longitudinal shaft of the chisel and the chisel is used to remove a cartilage graft from a surface of a bone. The cartilage graft includes a cartilage surface and a bony shaft.
The surgical method may further include transplanting the cartilage graft into the passage in the patella from the anterior surface of the patella to the posterior surface of the patella.
In another general aspect, a set of surgical instruments for repairing a tibial articulating cartilage surface includes a first instrument and a second instrument. The first instrument includes a channel having a longitudinal axis. The second instrument is mountable to the first instrument and includes a surface that is configured to be placed flush against the tibial plateau. The longitudinal axis of the channel intersects a surface of the tibial shaft and the tibial articulating surface, and forms a predetermined oblique angle with the tibial articulating surface when the surface of the second instrument is flush against the tibial plateau.
Embodiments of the set of surgical instruments may include one or more of the following features. For example, the set of surgical instruments may further include a guide wire configured to be inserted into the channel and to drill an opening in the surface of the tibial shaft along the longitudinal axis. The guide wire may be configured to drill a tibial passage from the opening in the surface of the tibial shaft to an opening in the tibial articulating surface. The drilled tibial passage has the predetermined oblique angle with the tibial articulating surface.
The second instrument may include an arm that includes the surface, with the surface being configured to be placed against the tibial plateau by passing the surface and a portion of the arm below a meniscus and above the tibia. In another implementation, the second instrument may include an arm that includes the surface, with the surface being configured to be placed against the tibial plateau by passing the surface and a portion of the arm above a meniscus and below the femur. The surface also may be in the form of a ring having a channel or it may have a solid surface.
The set of surgical instruments may further include a delivery instrument that is configured to deliver a cartilage graft into the drilled tibial passage. The delivery instrument includes an interior channel, which extends between an open distal end and an open proximal end, and a flange at the distal end. The flange is configured to be inserted into the anterior opening to deliver a cartilage graft through the interior channel into the tibial passage. The delivery instrument may include a window formed in a wall and open to the interior channel. By viewing the window, the cartilage graft can be visually inspected during delivery through the interior channel.
The set of surgical instruments may further include an insertion instrument that is configured to be inserted into the interior channel of the delivery instrument to advance the cartilage graft from the delivery instrument into the anterior opening in the tibia.
In another implementation of the set of surgical instruments, the first instrument may be a director handle and the second instrument may be a guide. The director handle includes the channel and a slot into which the second instrument is installed. The guide includes an arm and a distal foot, with the arm configured to be adjacent to a femoral condyle and the foot configured to be flush with a tibial plateau when the foot is pressed against the tibial plateau. The foot includes a surface including a pin projecting from the surface and configured to be pressed into the tibial plateau when the foot is pressed against the tibial plateau.
The set of surgical instruments may further include a tube configured to be inserted in the channel and to receive a guide wire for drilling a passage through the tibia to the tibial articulating surface. The passage forms an oblique angle with the tibial articulating surface. The oblique angle may be approximately 30xc2x0.
The set of surgical instruments may further include a drill having a central shaft, with the shaft being configured to be inserted over a guide wire to enlarge a hole drilled by the guide wire. The set of surgical instruments may still further include an offset tool that includes a handle having a distal end, a probe, and a guide. The probe is attached to the distal end and extends perpendicularly from a face of the handle. The guide is attached to the distal end, offset from the probe, and has an inner shaft with a longitudinal axis that is substantially parallel to the probe. The longitudinal axis of the guide is offset from a longitudinal axis of the probe by approximately 0.1 to 0.3 inches. More particularly, the longitudinal axis of the guide may be offset from the longitudinal axis of the probe by approximately 0.18 inches.
The set of surgical instruments may further include a chisel, a chisel guard, and a tamp. The chisel has an angled tip and a longitudinal shaft passing through the chisel and the tip. A longitudinal axis of the longitudinal shaft forms an oblique angle with a cross-sectional surface of the tip. The chisel guard has a shaft and a flanged end, and the shaft is configured to surround the chisel. The tamp is configured to be inserted into the longitudinal shaft of the chisel. The oblique angle may be approximately 30xc2x0.
The set of surgical instruments may further include a tapered bone plug compressor. The compressor includes a longitudinal shaft passing between a first opening and a second opening, and the diameter of the shaft increases from the second opening to the first opening.
In another general aspect, a surgical method of repairing a tibial articular cartilage surface includes placing a first instrument through a first incision so that the first instrument engages a surface of the tibial shaft, placing a second instrument through a second incision so that the second instrument is located on the tibial plateau, drilling a passage from the surface of the tibial shaft to the tibial articular cartilage surface, inserting a graft into the tibial shaft surface opening of the passage, and inserting the graft further into the passage. The passage passes between a tibial shaft surface opening and a tibial articular cartilage surface opening.
In the surgical method, the first instrument may include a channel having a longitudinal axis that is configured to intersect the surface of the tibial shaft and the tibial articulating surface. The second instrument is mounted to the first instrument and includes a surface that is configured to be placed flush against the tibial plateau. The longitudinal axis of the channel forms a predetermined oblique angle with the tibial articulating surface when the surface of the second instrument is flush against the tibial plateau. Drilling the passage from the surface of the tibial shaft to the tibial articular cartilage surface further includes inserting a guide wire into the channel in the first instrument and drilling an opening in the surface of the tibial shaft along the longitudinal axis. The surgical method may further include drilling the passage from the opening in the surface of the tibial shaft to an opening in the tibial articulating surface. The drilled passage may be at the predetermined oblique angle with the tibial articulating surface. The predetermined oblique angle may be approximately 30xc2x0.
The second instrument may include an arm that includes the surface. The surface is placed against the tibial plateau by passing the surface and a portion of the arm below a meniscus and above the tibia. In another implementation, the second instrument includes an arm that includes the surface, and the surface is placed against the tibial plateau by passing the surface and a portion of the arm above a meniscus and below the femur.
In the surgical method, inserting the graft into the tibial shaft surface opening of the passage may further include placing a delivery instrument into the tibial shaft surface opening. The delivery instrument includes an interior channel that extends between an open distal end and an open proximal end, and a flange at the distal end. The flange is configured to be inserted into the opening to deliver a cartilage graft through the interior channel. The delivery instrument may further include a window formed in a wall and open to the interior channel such that the cartilage graft can be visually inspected during delivery through the interior channel. Inserting the graft further into the channel includes inserting an insertion instrument into the interior channel of the delivery instrument to advance the cartilage graft from the delivery instrument into the tibial shaft surface opening in the tibia.
The set of surgical instruments provides numerous advantages. For example, using the patellar guide in a surgical procedure enables the surgeon to repair the posterior surface of the patella in a retrograde manner, which reduces the invasive nature of such a repair. Specifically, because the channel in which a replacement graft is to be inserted can be accessed from the anterior surface of the patella, the patella does not need to be turned over and accessed from the posterior side. In this manner, the procedure is less invasive. Because the channel can be drilled such that it is perpendicular to the opening of the channel on the posterior patellar surface, a cartilage graft should be harvested such that its cartilage surface is perpendicular to its bony length. Thus, when the cartilage graft is inserted into the channel, it will have the cartilage surface flush with the posterior patellar surface, which promotes healing and provides better results.
In using the set of surgical instruments for repairing damaged cartilage on the tibia in the knee, a channel is drilled from the anterior surface of the tibia to the tibial articulating surface of the knee joint. The guide and handle are configured to form a channel having a known angle with the tibial articulating surface. Thus, if a graft is harvested at the same angle and implanted in the channel, its cartilage surface will be flush with the tibial articulating surface in which it is placed.
The details of various embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.